The Collaborative International Dictionary of English v.0.48:

Mohawk \Mo"hawk\, prop. n.
   1. (Ethnol.) One of a tribe of Indians who formed part of the
      Five Nations. They formerly inhabited the valley of the
      Mohawk River.
      [1913 Webster]

   2. One of certain ruffians who infested the streets of London
      in the time of Addison, and took the name from the Mohawk
      Indians. [Slang] --Spectator. Macaulay.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Mohawk
    n 1: a member of the Iroquoian people formerly living along the
         Mohawk River in New York State
    2: the Iroquoian language spoken by the Mohawk
    3: haircut in which the head is shaved except for a band of hair
       down the middle of the scalp [syn: mohawk, mohawk
       haircut]